[Ironhawk]

Chazar said:
As "Major Changes" I would regard things like proper terrain effects or obstacle on the battle grounds, a new unit attribute, a new resource, proper modelling of the different native races within a province and their migration, new buildings with a proper function, a renewed yet manageable battle setup, etc. ...so anything which directly alters gameplay. Something that is not straightforward to guess and what would make me curious!

I think these are all fine ideas, IMO. Tho from the info we have at hand I dunno if we can extrapolate on the existence of any of them.